The present invention relates generally to laser amplifier buffers and more particularly to laser amplifier buffers which may be employed in double-pass amplifier chains which transmit laser energy having two polarization components. Also, the present invention relates to electro-optic Q-switches for laser oscillators.
In high-gain laser amplifier systems which employ a plurality of laser amplifiers, a buffer is necessary between amplifiers to prevent superradiant lasing. Previous buffer arrangements generally employ an electro-optic switch which is sandwiched between polarizers on either side. However, these devices operate in a manner which passes only one polarization. Therefore, these arrangements are limited to use with single-pass laser amplifier chains.
Double-pass amplifiers offer improved energy extraction from two passes through the amplifier chain. However, the double-pass amplifier requires that a buffer arrangement be present adjacent to the totally reflecting mirror of the laser amplifier which must transmit both polarizations. Therefore, the above-mentioned conventional amplifier buffers may not be employed in double-pass systems.
Electro-optic switches, or Q-switches are employed in laser oscillators to provide a technique which keeps the gain of the oscillator low while the population inversion is being increased, and switches the gain to a high value when the population inversion is maximum. This technique creates a single pulse at high peak power. Electro-optic switching action may be achieved with Kerr cells, or a Pockels cell, or the like. However, no electro-optic Q-switching device has been employed in a laser oscillator which switches the gain high for both polarization components to produce an unpolarized laser output.